How, if possible, can you identify bad eggs in Pokemon white and black? To be specific, what are the differences from normal eggs other than the name "bad egg", is it identified the same way for generation 4 games (d/p/platinum/ss/hg), and finally, can they be moved to an empty pc box in black/white? I am trying to help a friend, so I appreciate any help on this subject.

sorry for the triple comment, but i found confirmation on the storing the bad egg alone in a empty pc box works as an isolation technique. so if the egg is a bad egg, i just tell my friend to put it in an empty box and use his A.R. to clone another pokemon over it (overwriting it) and then delete the clone. right?

true, but there are also a lot of people saying that it was a temporary fix until they used an A.R. code to "overwrite" the bad egg and remove it. Also in my platinum version I got a bad egg from breeding a pokemon one of my friends traded me (turns out it was created in Pokegen) with a ditto. I borrowed his A.R., overwrote the bad egg, and deleted the pokemon that was in the egg's place. I haven't had a problem with the game since.

I guess that is all the answer I am going to get. Turns out that my friend's egg hatched in to a bad egg, so I had him put it in to an empty box in his pc, use his A.R. to clone another pokemon over it to overwrite it, and then delete the clone. He has had no problems since. So I guess that my question is answered. thank you to everyone who helped me in answering this question.

Thank you Trachy for moving this for me, and sorry for placing this in the answers section before. i was distracted with an online conversation with my dad.